The so-called “Dark Days” scheduled for the Medicare claims payment system changeover might cause more than just an inconvenience for your billing. During the outage, which was bumped from May 15 to May 22, “many systems will not be available,” stresses HHH Medicare Administrative Contractor CGS on its website. “You may continue to submit electronic claims on May 19-22, but they will not continue to process until the Fiscal Intermediary Standard System (FISS) nightly cycle runs on Tuesday, May 23rd,” the MAC says. HHH MAC National Government Services, however, says “claim submission will not be available from Friday evening, 5/19/2023 through Monday, 5/22/2023.” Tip: For FISS/DDE, “please continue to use Option 5,” NGS instructs. “Starting 5/23/2023 use Option 2,” the MAC says. “We do not expect any delays to your payments,” CGS maintains. However: “If you feel the dark day period caused a late NOA/NOE submission, you must provide the appropriate supporting documentation with the associated final claim,” CGS instructs. Instructions for obtaining exceptions for late Notices of Admission for home health claims are at https://cgsmedicare. com/hhh/pubs/news/2022/12/cope3767.html and for late Notices of Election for hospice claims are at https:// cgsmedicare.com/hhh/education/materials/requesting_ exception_untimely_noes.html.